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volume of a cylinder is 1540 cm³ and the difference of its height and radius is 3 cm, then find the total surface area of the cylinder.​

User Tjfo
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Answer:

Let's assume the height of the cylinder to be 'h' and its radius to be 'r'. We can use the given information to form two equations.

First, we know that the volume of the cylinder is 1540 cm³:

V = πr²h = 1540

Second, we know that the difference between the height and the radius is 3 cm:

h - r = 3

Using the second equation, we can solve for 'h' in terms of 'r':

h = r + 3

Substituting this into the first equation, we get:

πr²(r + 3) = 1540

Expanding the left side of the equation and simplifying, we get:

πr³ + 3πr² - 1540 = 0

We can solve for 'r' using the cubic formula, but it's easier to notice that 'r' must be close to 10. We can try different values of 'r' until we get an answer close to 1540. If we try 'r' = 10, we get:

π(10)²(10+3) = 3300π

So, the radius is approximately 10 cm and the height is approximately 13 cm.

To find the total surface area of the cylinder, we need to find the area of the top and bottom circles and the area of the curved surface. The area of each circle is πr², so the total area of the circles is:

2πr² = 200π cm²

The area of the curved surface is the circumference of the circle times the height of the cylinder, or 2πrh. Substituting the values of 'r' and 'h' that we found earlier, we get:

2π(10)(13) = 260π cm²

Therefore, the total surface area of the cylinder is:

200π + 260π = 460π ≈ 1442.4 cm²

So, the total surface area of the cylinder is approximately 1442.4 cm².

User Oleksandr Loushkin
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